Hair dyeing method using gelatin as a dye resist



United This invention relates to hair dyeing.

If hair is to be dyed in a reasonbly uniform manner account has to be taken of the non-uniformity of the individual hairs or filaments, for at its root part a filament is less receptive to dye than at the mid-part, and this in turn is less receptive than the end part. If the hair to be dyed has been previously bleached or permanently waved, obtaining acceptable uniformity of colouration over the lengths of the filaments demands great care, for such previous treatments increase the natural tendency of the filaments to become dyed to different extents.

With hair that is to be dyed for the first time this difficulty can be met by applying the dye in stages: to the root parts first, to the mid-parts next, and finally to the end parts, so that each part of the filament remains in contact with the dye for a time inversely proportional to its receptiveness to the dye. This needs skill. With subsequent dyeings, only the re-growth subsequent to the previous dyeingthat is, only the root parts normally has to be brought into contact with the dye, and care must be taken to avoid dyeing more deeply the other, alreadydyed parts of the filaments. The need for skill in this operation can be reduced considerably if there is applied to the already-dyed parts of the filaments a protective coating of non-toxic hydrocarbon material, such as petroleum jelly or mineral oil. However, since such material is water-insoluble, it is very difiicult to remove from the hair subsequently.

The present invention provides a method of hair dyeing by which an acceptable uniformity of dyeing can be conveniently obtained.

According to the invention, the hair to be dyed is first coated, at those parts of the filaments which it is desired should not come into contact with the dye, with a protective coating of a water-soluble or water-dispersibie protein.

The protein can also be applied to the forehead, to reduce staining of the forehead by the dye.

The preferred protein is gelatin. This is conveniently applied to the hair in the form of an aqueous composition such as a paste or viscous liquid optionally containing a thickener such as sodium alginate.

The following example illustrates the use of the invention in dyeing a head of grey hair which had been dyed 4 weeks previously. There was thus a re-growth amounting to about 1 cm. of each filament to be dyed.

Example The hair was first shampooed in the usual way, and the previously dyed parts of the filaments were then coated with gelatin by applying to them, by hand with combing,

-an aqueous paste composed of gelatin (6 parts), sodium alginate (4 parts), salicylic acid (preservative; 0.25 part) and water (90 parts). The paste was also applied to the skin on the forehead, immediately below the hair line.

tates Patent 6 3,193,465 Patented July 6, 1965 ice A conventional hair dye composition, containing a nitro hair dye and a shampoo base, was then applied to the hair in themanner that would be followed by a user at home: that is to say, without the accurate siting at the re-growth and without the avoidance of overlapping onto the previously dyed parts that would be achieved by a professional hairdresser.

After 10 minutes the hair was then rinsed with Water and shampooed to remove the gelatin coatings from the previously dyed parts of the hair and from the forehead. These coatings had taken up dye which would otherwise have dyed or stained those parts which they protected. The filaments were found to be of an acceptably uniform colouration, and there was found to be substantially no staining of the forehead.

What is claimed is:

1. A method for dyeing hair which comprises applying gelatin on a first part of a hair filament but not on a second and remaining part of a hair filament; and applying independently a dye to the entire hair filament; said second part of the hair filament being dyed Without dyeing said first part of the hair filament thereby.

2. A method for dyeing hair on a head which comprises applying gelatin on a previously dyed end portion of the hair but not on a previously undyed root and remaining portion of the hair; and applying independently a dye to both the end portion and the root portion of the hair; said root portion being dyed without dyeing further said end portion of the hair thereby.

3. A method for dyeing hair on a head which comprises applying an aqueous gelatin composition on a previously dyed end portion of the hair but not on a previously undyed root and remaining portion of the hair; applying independently a dye to both the end portion and the root portion of the hair; and shampooing the hair to remove said aqueous gelatin composition; said root portion being dyed without dyeing further said end portion thereby to provide hair with a uniform color in the root and the end portions.

4. The method according to claim 3 in which the aqueous gelatin composition is a paste comprising sodium alginate, salicylic acid, gelatin and water.

5. The method according to claim 3 in which the aqueous gelatin composition is also applied to the forehead to prevent staining by the dye subsequently applied to the hair.

References Cited by the Examiner UNITED STATES PATENTS 1,754,287 4/30 Shoemaker 810 1,884,015 10/32 Lougovoy 167-87 2,056,135 9/36 Butler 167--87.1

FOREIGN PATENTS 409,336 4/34 Great Britain.

OTHER REFERENCES Merck Index, 6th edition, Merck and Co., Inc., Rahway, New Jersey, 1952, p. 870.

JULIAN S. LEVITT, Primary Examiner.

FRANK CACCIAPAGLIA, IR., LEWIS GOTTS,

- r I Examiners. 

1. A METHOD FOR DYEING HAIR WHICH COMPRISES APPLYING GELATIN ON A FIRST PART OF A HAIR FILAMENT BUT NOT ON A SECOND AND REMAINING PART OF A HAIR FILAMENT; AND APPLYING INDEPENDENTLY A DYE TO THE ENTIRE HAIR FILAMENT; SAID SECOND PART OF THE HAIR FILAMENT BEING DYED WITHOU DYEING SAID FIRST PART OF THE HAIR FILAMENT THEREBY. 